Apparatus for assembling rubber bearings



April 24, 1951 P. C. HUTTON APPARATUS F'OR ASSEMBLING RUBBER BEARINGSFiled Aug. 5, 1947 2 Sheets-Sheet l Pi/ Haifa/7.

A April 24,'` 1951 P. c. HUTTQN 2,550,564

APPARATUS RoR AssEMBLING RUBBER BEARINGS Filed Aug. 5, 1947 l '2sheets-sheet 2 i Wal/VEKS.

Patented Apr. 241951 23550257621- iullAltilllUs FoltlAssEMBLING .RUBBERBEARINGS- Philip4 fo.- Hiittoii, London,y England, assigner tosileii-tbloo, Limited,1 London, Eli-gland, a eo'ianyf Great `BritainApplieat'ioii Aiigiist 5, 194i, serial No.- 766,204

l 'The lresilt invention relates t6 an apparatus 'fr and method 'ofassembling rubber 'bearings' f 'tlie' type employing external and innereoiieerie 'trie' @"lin'drieal bearing'mernbers having Aa radially o"1iss`ed arid aXially elongated yielding rub b'' bushing 'tlirelietttfeeA j 'In 'the past, 'rubber 'bearings of the type li'le'il tioned haveusually been assembled by' two op# eratiorls. In tile r's't operation,therubber"bursh= il'g 4i's` irls'el't'd Wtlliri th outer`bea`riglrleiber by forcing ittliifoiieli a conica-l tunnel, which reeluces the outside diameterf tlleb'usllng. The inner' bearing member 'iStli'er'i fitted on the rear fld'of a corneal iiiilicli aild the purieh'sy foreed tl'iliigli tilev meiin'g'lll the `bushing' 't6 e'ilar'ld it'siiltelal diameter arid insert tll'eimer 1l".ler`riA bervvi'thin thebushing. rThis reduees-ttijeiredietl tlfkrie'ss of ythe bushing "an'd(silice rubber", like' a liquid, is 'substantially incompressible)'crree' Spolidingly'increase's its 'airiallerlgtlt Where-'aw urate'lengthwise positioning 'f the bushing be?- tWer th'e' bearing membersiS *not important, it has" 'been found that Satisfactory' lcica'tioll isaChiel/edhlerely by'perfo'lilllg thi?4 abv tW'O op: eratioils athigli'speed Vill the 'presence' f a suit= able lubricant, sueli as mWater or'petroleum jelly'. However, 'where lengthwise ,location fis'weiitieal,other ibedieiltsfifillstie relied 'lill``i. For 'this purpose', it hat'been proposed that diirliretne second Yop'felation orte enti :ofbustling jte eil-- eagedwby annular lshoulderrvvliio'li liiriit's axial'`movemerlt of the bushing under theirictilial' for-@estimated by passageoi tire punchtlirpu'gh the bushing'. This, however, jdb'es 'not`ioslit'iyely" lobatetle bus'ling, because there 'can b'e as` surancethat-the bustling' will be moved against the Shoulder. *I'n' addition,difficulties "'aree'rl'el countered W'- 'a tendency te lfiinch apart-fofthe rubberbushing between the purieh and Ltile' ari-'- nular shoulder.

The above 'diflieulties `are Agreatly aggravated in the -production Yof'the .form lof bearing" `disclosed in applicants copendng application onlRubber Bearing, Serial No. 766,205, filed concurrentlyT herewith, nowPatent No. 2,517,791, August 8,

which project beyond the ends of the outer bearl which shouldend in axed po,- herewith, now "Patent siti'lerig'thwise with respect to theinei mellib'erin order to cci-operate with abutritsliolmember. l I y' nAccordingly, it i's on'eob et o'i the present 1950, in which the bushinghas end extensions ing member and y I* n No. 2,517,791, August 8,

ders Avviiie'h lare 4stilisequer'itly fixed to the yeti to Aprovideimproved lrret'tiis" afid 3 Clttin'lsv (Clt 529-235) fie of the assembly613er 2 Y for positively leatinef the rubber 'bu's'l'irlgleigtl Wisewith respect to the' bearing.

Ariotliel 'object f 'tl'le 4fllerltiorl S` 't'o prei/lit the`possibility 'of' piiic'liig the `l`ubber bushing during 'the 'assemblyoperation.

Alurtner object of tl'ie invention is to provide improved means "frvinsuring 'proper latin f the rubber bushing 'in 'the 'external'b'alil'g lele ber during the rst 'ope'ratili. V v

Another obj ec't O f 'tl'e irleiitli is t0 provide epperetus of thety'ee mentioned eti-d eiij essertibly 'method Whioli arev peculiarlysuited t 'tile assembly o'f 'the type f bearing diSCl'sd alii; plicarltsabove mentioned application.

'Other objects and advantages di the veiition Will become ap'palr'er'ltfrom tl'i follollvi'i'll,r Specification, the aeibailyiilg 'drawings'arid th 'appended olainis.

in the drawinesf K Figure' 1 illustrates tle frr f bai diselosed inapplieents above iiieiotioiied contending application, fior virilelitrie orefejrrejd torni of lrieh'arl'srr'l' illustrated arid describedvl'ri is er'riplo'ye'd;r v

Figure '2` shows" the free 'state of tile rubber bushing einplyed in thebearingZ irl' Figure l;

Figure V21 is a longitudinal 'sftin Showing' tlel tl'ohali's employediii berfo'fing the 'c assembly operation; and

Figure 5 i's a View Sl m'lar t6 Figure 4, 'sliilvin'g tl'leV Darts ir'lthe 'position they lipy t the set roftli iii ere@ detail iii eisp-lieatsabove metioiieil oopeiidig epiilioation, torni of bearing illustratedArrigiiiejl eoiiipiises iiiiier sleeve l ao eil oiiter vsleeve' `2betweeiji la.

This clearance, las set forth in said application, greatly enhances theaxial load carrying capacity of the bearing.

The internal diameter of the rubber bushing 3 is less than the externaldiameter of the internal sleeve I, with the result that it is necessaryto expand the bushing in order to assemble it on the inner sleeve.

In the first operation, the rubber bushing 3 is inserted within theexternal sleeve 2 by the mechanism illustrated in Figure 3. As thereshown, the mechanism comprises a press of any suitable constructionhaving a bed or platen 6 and a plunger 1. In accordance withconventional construction, the plunger 'I is movable toward and awayfrom the platen by any suitable means, such as an air cylinder (notshown). The parts are shown in the position in which the plunger I hasmoved to its maximum extent toward platen 6. The plunger 'I is securedto a pusher 8 by any suitable means, such as a collar 9 which is clampedto the plunger and pusher by means of bolts I and II. Surrounding thepusher 8 is a housing I2 having an enlarged cylindrical bore I3, thelower end of which merges with the upper larger end of a frusto-conicalfunnel-shaped bore I4, the lower smaller extremity of which is of thesame internal diameter as the internal diameter of the outer sleeve 2 ofthe bearing. The

housing I3 is provided adjacent its lower end with a counterbore of thesame diameter as the external diameter of the outer sleeve 2, whichcounterbore terminates in a shoulder I5, adapted to engage the end ofthe outer sleeve. The central cylindrical bore I3 in housing I2 has atone side an opening I'I of sufficient size to permit insertion of therubber bushing shown in Figure 2.

It will be appreciated that the housing I2 is slidable on the pusher 8and that when the press is open the lower extremity of the pusher 8 islocated above the opening II, thus permitting insertion of the bushing 3through the opening II.

The lower end of the pusher 8 is provided with an enlarged head I8 ofthe same diameter as the intern-al diameter of the sleeve 2. The head I8hasan annular counterbore I9, adapted to receive the projection 4 of oneend of the bushing, and a, central pilot 20, which is adapted to projectWithin the central opening in the bushing. The pilot `2i) is ofapproximately the diameter Vwhich the central opening in the bushingwill assume when the bushing is inserted within the sleeve 2. An airoutlet passageway 2l is provided within the head I8 to permit dischargeof air trapped within the annular counterbore I9.

, The platen 6 is provided with a die 22 having a central bore 23 inwhich is fitted an adjustable head 24, adapted to engage the lowerextremity of the bushing upon the completion of the rst assemblyoperation. The head 24 is provided with a counterbore 25, adapted toreceive the extension 4 on the lower end of the bushing.Y The head 24 isadjustable by means of a screw 26,

which is threaded within the die 22 and locked in position by means of anut 2.

In operation, the mechanism shown in Figure 3 forms the rst assemblyoperation in the ollowing manner. When the press is fully open, theshoulder 28 on the head I8 of the pusher engages an internal shoulder 29within the housing I2 and slightly elevates the housing to permit theinsertion of the sleeve 2 over the end of the head 24 in the positionshown in the drawing. Bushing 3 is then inserted through the opening I'Iand is held in approximately the proper position in alignment with thepilot 20 on the then elevated pusher 8 by its engagement withcylindrical bore I3 of the housing. The press is then operated to causethe plunger I and pusher 8 to move downwardly. This permits the housingI2 to move downwardly over the upper end of sleeve 2, as shown in Figure3. As the plunger continues to move downwardly, the pilot 20 enters thebushing 3 and the head I8 forces the bushing downwardly through thefrusto-conical funnel I4 and into the sleeve 2. This radially contractsand to a limited degree axially elongates the bushing 3 to the formillustrated in Figures 3 and 4. The downward movement of the bushing islimited by its engagement with the head 24, thus insuring properlengthwise location of the bushing relative to the sleeve. The pilot 29and annular recess I9 in the head I8 serve to prevent cocking orwrinkling of the bushing during the 0peration, which might otherwiseresult.

yOn completion of the first operation, the press is opened and thesleeve 2, with its associated bushing 3, is removed from the mechanismand transferred to the mechanism shown in Figures 4 and 5, whichperforms the second operation.

The second operation, which involves the insertion of the inner sleeve Iwithin the central opening in the bushing 3 and a consequent substantialradial expansion of the bushing 3, is carried out on a press similar tothat employed in connection with the first operation but employingdifferent tooling. Thus, as shown in Figure 4, the press includes a bedor platen 30 and a plunger 3|, which is adapted to be moved toward andfrom the platen 30 in any suitable manner. Mounted on the platen is adie 32 having a central bore 33 in which is fitted a head 34 having avertical extending pilot 35. The head 34 is secured in position on thedie by means of a threaded stud 36, which is threaded into the die andlocked in position relative thereto by a nut 31. The inner sleeve I ofthe bearing is inserted over the pilot 35 when the press is open, andthe reduced pilot end 38 of a tapered plunger 39 is then tted Within theupper end of the sleeve I, so that these parts assume the relativepositions shown in Figure 4. It will be understood that at that time theplunger 3I and associated parts, hereinafter described, are in theirfully raised position and, therefore, located entirely above the roundedend 40 of the tapered plunger 39.

During the second assembly operation, the outer sleeve 2, with itsassociated bushing 3, is supported within a cylindrical counterbore 4Iformed in the lower end of a housing 42, which is ixed to the plunger 3Iby means of a collar 43, the collar being clamped to the plunger andhousing by means of bolts'44 and 45 and associated straps.

Slidably tted within the housing 42 is a piston 46 with the sameexternal diameter as the in#v ternal diameter of the external sleeve 2.The piston 46 at its upper end is provided with an enlarged shoulder 4'Iadapted to seat against a corresponding internal shoulder 48 formedwithin the housing. Piston 46 is of annular construction, having acentral cylindrical bore 49 of suicient'diameter to receive the lowerend of the tapered plunger 39, which is of the same,

diameter as theexternal diameter of the inner sleeve I. The piston 46adjacent its lower end is also provided with a counterbore 50 adapted toreceive the annular extension 4 on the bushingA `flaredmouth of ther'ecess 4i.

@rfre the rushing is expefieedfey mepur-ien 319i important feature ofthe invention rests the 'fact that the counterbore is of' greater' axiallength than the length of the extensin 4 andthe resulting projecting end5|- of piston 46 is of less radial thickness than the radial distarieeZbetween the inner' and outer sleevesv l= and n assembly and 'greaterthan the relatively Small clearance space' 5 iii the a'JSsei'nbledabear`g'.

The annular piston- 46 is urged downwardly by Vrelatively heavy spring52, the upper end of` w ch is seated againstr an adjustable collar 535,

lis threaded within an upper threaded perti'on of the-.housing 42. A Theoperation ef the mechanism shown in e ilv is las follows. With the pressccm-pletehly open, the external Sleeve 2, with-its-associatedl y3, ist'ted over' the Aend of the taperedpli'nch 39 and thus' held inallg-'rfliiienl'jvr with the The 4press is@ then` closed. The upper endof sleeve 2 is nrstseatedwithm the recess il surrounding the lewer endof piston 46 and the projection '4 extends into the counterbore 5B.Thereafter the press' forces the sleeve and bushing 3 downwardlyoverVthe tapered plunger 3e and inner sleeve l, until the parts vassume theposition 'shown Vin Figure 5, in which the lower end of the housing i2and outer sleeve 2 are seated against the upper sur` face of the die 32.This greatly expands them--v ner diameter oi the bushing 3 and causes itto f elongate axially. Before the parts rea-ch the po- "sition in Figure5, the lower end of the bushing 3 abuts against the bottom of a shallowrecess 54 formed in the die 32.

Prior to such engagement and during the downward movement of theplunger, the frictional force exerted on the rubber bushing 3 by thetapered plunger 39 and the sleeve l tends to force it upwardly relativeto the external sleeve, kbut the strength of the spring 52 is more thansufcientto overcome such force, with the ifesult that the upper end ofthe bushing 3 is held against movement axially with respect to theexternal sleeve to the .position shown in lFigure '4 until after thelower end of the` bushing engages the `bottom of the recess 54.Thereafter, as the plungercontinues to move downwardly, the body of therubber constituting the bushing 3 is cornpletely enclosed. Since rubber,like other liquids', is substantially incompressible,,it/must,therefore, expand in an axial direction upwardly with reference to thesleeve 2. Consequently, during the nal closing movement of the press,the rubber bushing 3 expands upwardly, forcing the piston 46 upwardlyrelative to housing 42 against the force exerted by the spring 52, asindicated by the nal position of the parts illustrated in Figure 5.

Since the bottom of the recess 54 is in a fixed position relative to thelower ends of sleeves I and 2, it will be apparent that the apparatusresults in a positive lengthwise vlocation of the bushing relative tothe sleeves. Since in producing the form of bushing shown in Figure 1 itis desirable to have the rubber bushing terminate flush with the ends ofthe inner sleeve i, this relationship may be insured by vertical adjust-1 ment of head 34 relative to the die 32.

In assembling the form of bushing shown in Figure l, it is essentialthat the extremity of piston 46 engage the shoulder on the bushing atthe juncture of the central body portion of the bushtively locate thecompressed central portion of' the bushing in spaced relation to theends of the outer sleeve. Qn the other hand, when the radial clearancespace 5- in the assembling is as small as that illustrated inY Figurel,` it is not possible t'oprovide an annular piston having' a radialthickness as small as the clearance space since, in that case, the:piston mightv be forced into a position between `the enlarged centralportion of the bushing and the external sleeve and be caught by therelatively high radial pressure exerted by the compressed rubber. Inaddition, even in` the absence oi extensions 4, it is not possible toprovide a piston 46 having its annular extremity of the-same radialthickness-as the space between the inner and outer sleeves l and 2since,V in thatl case, Vthere :would be danger of pinching a por V tionof the rubber between the tapered plunger' 39 and the inside of thepiston 4'6'. Accordingly, asY previously indicated, the reducedextension 5I on the annular piston is made of a thickness greater thanthe clearance space 5 andv substantially less than the space betweensleeves l and- 2.1 As a result,- when the parts assume their fullyclosed position shown in Figure 5, the annular projection 4 of thebushing is radially compressed and axially elongated beyond the upperend ofthe inner sleeve l, in the manner shown in the drawing. When thepress is opened and theconipleted bushing extracted from the housing 42,the upper extension 4 will snap back into the'- position shown inFigure 1. Similarly, the lower extension 4 which will have beenpartially compressed and! flattened by the bottom of the recess54,--'will likewise assume the position shown in Figure lif the heightof the head 34 is properly 'adjusted with respect to the die 32.

By providing the counterbore 50 in the annular' plunger 46 into whichthe extremity ci the rbushing may expand Iwithout being pinched by thetapered plunger 39, theapparatus of the present invention eliminates thedifficulties encountered` with prior attempts to utilize shoulders tohelp locate the bushing in proper longitudinal position and at the sametime produces an assembledy bearing in which the bushing is positivelylocated lengthwise with respect to both sleeves.-

The apparatus of the present invention may be employed with Vsuccess toassemble radially compressed bushings which do not yhave project'- ingend portions 4. In such case, the upper `endA ci the bushing wouldterminate flush with the' lower end of the annular piston 46 when theparts are in the position shown in Figure 4. It is still essential,however, to provide the counterbore 50 to prevent pinching of the rubberbetween the piston and the plunger 39. While in Figures 4 and 5 thetapered plunger 39 is shown mounted on the die by means of the innerbearing member which is being inserted, it :will be apparent that it maybe made of sufficiently small diameter to receive the inner bearingmember and be mounted on the die independently of the bearing member,provided the end of the bearing member is suitably chamfered or aseparate chamfered ring is placed on the cylindrical shank of theplunger 39 immediately above the inner bearing member to facilitateentry of the bearing member into the bushing.

It will be apparent that while. as described above, the apparatus ismounted vertically with a stationary platen and an upper movableplunger, the relative position of the parts may be reversed or theapparatus may be mounted horizont'ally. In addition, either the platenorthe plunger may remain stationary and the other moved relative theretowithout departing from the principles or advantages of the invention.

It will be understood that in accordance with conventional practice inassembling radially compressed bushings, it is desirable to operate thestruction may be indulged in Without departing from the spirit of theinvention or the scope of the appended claims.

What is claimed is:

1. An apparatus for holding an outer bearing member having a rubberbushing tted therein during the insertion of an internal bearing memberof a diameter larger than the internal diam-` eter of the bushing andprovided with a pointed pilot endpiece adapted to expand the bushingduring insertion, said apparatus comprising a supporting member adaptedto engage one end of the outer bearing member and hold it against axialmovement in one .direction relative to the supporting member and anabutment member carried by the supporting member and having an annularend portion adapted to engage the corresponding end of the bushing, saidend portion having an external diameter which will closely t Within theouter bearing member and an internal diameter which is materiallygreater than the external diameter of the inner bearing member.

2. An apparatus for holding an outer bearing member having a rubberbushing tted therein during the insertion of an internal bearing memberof a diameter larger than the internal Adiameter of the bushing andprovided with a pointed pilot endpiece adapted to expand the bushingduring insertion, said bushing having an annular axial projection ofreduced outside diameter forming a shoulder at one end, said apparatuscomprising a supporting member adapted to engage one end of the outerbearing member and hold it against axial movement in one directionrelative to the supporting member, and an abutment member carried bysaid supporting member and vhaving' an* annular end portion adapted toengage the corresponding end of the bushing, said end portion having anexternal diameter which will closely t Within the outer bearing memberand an internal diameter which will t over the bushing projection priorto insertion of the internal bearing member.

3. Apparatus for holding an outer bearing member having a rubber bushingtted therein during the insertion of an internal bearing member of adiameter larger than the internal diameter of the bushing and providedwith a pointed pilot endpiece adapted to expand the bushing duringinsertion, said bushing having an annular axial projection of reducedoutside .diameter forming a shoulder, said apparatus comprising asupport adapted to engage one end of the outer bearing member and holdit against axial movement in one direction, an annular piston carried byand slidable with respect to said support, said piston having an annularaxially projecting portion adapted to engage the shoulder at thecorresponding end of the rubber bushing and form an axial abutmenttherefor, said portion having an external diameter which will closelyiit within the outer bearing member and an internal diameter at itsbushing engaging end which is materially greater than the externaldiameter of the inner bearing member and which is less than the externaldiameter of said bushing projection in the completed bearing, resilientmeans carried by said support and acting on said piston in a directionto urge the piston against the bushing, and means for limiting movementof said piston in said one direction relative to said supporting member.

PHlLIP C. HUITON.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,062,626 Wiedrich May 27, 19131,739,270 Thiry Dec. 10, 1929 1,904,931 Rosenberg Apr. 18, 19331,913,933 Lamborn et al June 13, 1933 1,959,254 Zerk May 15, 19342,003,412 Alden et al. June 4, 1935 2,031,797 Tarbox Feb. 26, 19362,115,437 Welker Apr. 26, 1938 2,379,508 Dodge July 3, 1945

